def bit_option(value, option):
    '''设置选项'''
    return value | option


def bit_clear_option(value, option):
    '''清除选项'''
    return value & ~option


def bit_is_option_set(value, option):
    '''是否被设置'''
    return bool(value & option)


if __name__ == '__main__':
    import base64
    a="SGVsbG8gV29ybGQh"
    s=base64.b64decode(a)
    print(s)

